This invention relates to a method and therapeutic adhesive patch product for treating pimples and/or acne.
Acne is a common inflammatory pilosebaceous disease characterized by comedones, papules, pustules, inflamed nodules, superficial pus-filled cysts, and (in extreme cases) canalizing and deep, inflamed, sometimes purulent sacs. Acne involves an interaction between hormones, keratinization, sebum, and bacteria that somehow determines the course and severity of acne. It often begins at puberty, when the increase in androgens causes an increase in the size and activity of the pilosebaceous glands. The earliest microscopic change is thought to be intrafollicular hyperkeratosis, which leads to blockage of the pilosebaceous follicle with consequent formation of the comedo, composed of sebum, keratin, and microorganisms, particularly Propionibacterium acnes. Lipases from P. acnes break down triglycerides in the sebum to form free fatty acids (FFA), which irritate the follicular wall. Retention of sebaceous secretions and dilation of the follicle may lead to cyst formation. Rupture of the follicle, with release of FFA, bacterial products and keratin constituents into the tissues, includes an inflammatory reaction that may result in abscess that heals with scars in severe cases. When the condition is less severe, it may merely involve an occasional isolated pimple. However, the underlying pathology is similar to that described above.
Current treatment begins by washing of the skin. However, even vigorous washing of the skin leaves behind billions of bacteria, yeasts and fungi that cannot be dispossessed no matter how vigorously one scrubs. Bacteria which is normally found deep in the hair follicles is harmless most of the time. However, during adolescence, when the sebaceous glands become particularly active, these bacteria can proliferate and cause an outbreak of acne. Current treatment often includes the use of specific follicular drugs such as benzoyl peroxide or retinoic acid; the removal of comedones; or the use of antibodies such as tetracycline, erythromycin, chlorohexidine gluconate, or oral isotretinoin. Present therapeutic methods are generally recognized as not entirely satisfactory. After treatment, many patients still continue to suffer from the symptoms of acne or pimples.
In view of these and other deficiencies of the prior art, it is an important object of the present invention to provide a treatment for acne or pimples that is safe and can be used by the patient for effectively relieving or improving one or more of the symptoms of acne or pimples.
Another object is to provide an adhesive patch for treating pimples and acne.
These and other more detailed and specific objects of the present invention will be better understood by reference to the following figures and detailed description which illustrate by way of example of but a few of the various forms of the invention within the scope of the appended claims.
The present invention provides a means of reducing extracellular fluid volume within the diseased skin in and around a pimple or acne outbreak where extracellular fluid accumulates and is associated with an infiltration of white blood cells. This reduction in volume is produced by contact with a hydrophilic hypertonic patch or gel over the diseased tissue to produce an osmotic imbalance between the liquid within the inflamed skin and the hydrogel layer within the patch. This osmotic imbalance draws fluid from the low concentration in the acne-infected skin to the high concentration in the hypertonic hydrogel. This invention therefore concerns a method for treating the skin disorder acne as well as one or more isolated pimples by applying directly to the diseased skin a flexible hypertonic hydrophilic moisture-containing patch. The patch includes a backing such as paper, cloth or plastic that acts as a support for the patch and a water-based hypertonic hydrogel layer applied to the backing that preferably has a tacky pressure-sensitive adhesive surface which bonds to the skin. The hydrogel layer bonds to the skin surface and forms a water bridge between it and the skin. The hydro bond allows the flow of fluid from the skin, which has a lower osmotic pressure than the osmotic pressure in the hydrogel layer.
The hydrogel layer comprises water and, as a thickening or gel forming agent, a hydrophilic natural or synthetic polymer dispersed in the water. The polymer can comprise a high molecular weight hydrophilic carbohydrate such as karaya, cornstarch, or kelp gel and/or a synthetic hydrophilic polymer such as polyacrylamide, a polyionic gel, or polyacrylic acid. A humectant such as an alcohol containing two or more hydroxyl groups, i.e., a polyhydric alcohol, is preferably employed to keep the adhesive layer moist. Any water soluble solute such as salt or an alcohol is dissolved in the water in a quantity sufficient to raise the osmotic pressure above that of the underlying tissue of the patient; namely, to a value over about 308 mOsmol/L so as to maintain the adhesive hydrogel layer in a hypertonic state with respect to the underlying tissue of the body. The hydrogel preferably, but not necessarily, has adhesive characteristics to bond the patch to the skin. Alternatively, the patch can be held against the skin by a sheet of adhesive tape, i.e., a bandage, connected thereto that is bonded to the skin on either side of the patch or by a non-adhesive wrap or binder. The hydrogel hydrates the outermost layer of skin. Consequently, the hydrogel adhesive, when applied to a patient, forms a hydrophilic bridge with the patient""s skin which allows fluid transport between the skin and the patch across the hydrophilic bridge. With the patch in place on the skin, the fluid in and around the skin disorder is then transported from the skin to the hydrogel layer by osmotic pressure to thereby improve or entirely relieve one or more of the symptoms produced by the pimple or acne.
Another aspect of the invention is the hypertonic moisture-containing adhesive patch itself. The patch as noted above contains a flexible backing and a lower hydrophilic, pressure-sensitive adhesive layer containing water, a hydrophilic polymer dispersed in the water, and a dissolved substance. The relative amounts of the solute and solvent are adjusted such that the osmotic pressure of the patch is above that of the underlying tissue of the patient so as to maintain the adhesive hydrogel layer in a hypertonic state. The tacky surface of the adhesive layer wets the skin and creates the hydrophilic bridge with the patient""s skin. This allows the free transport of fluid, especially the extracellular fluid contained in the pimple, across the hydrophilic bridge into the patch.